Such brake boosters are widespread and are known, for example, from WO0061416A1, which is incorporated by reference or WO2004101341A2, which is incorporated by reference.
The booster housing of such brake boosters usually comprises two cup-shaped housing shells which are arranged in series along a brake booster central axis.
Brake boosters of the generic type have connecting pins which are arranged in the booster housing in an axis-parallel fashion with respect to the central axis and project through the booster housing with at least one end section, but usually with both end sections, from the inside to the outside. At these end sections of the connecting pins, master brake cylinders are then mounted and/or the brake booster is attached to the vehicle, with the result that during operation the booster housing is clamped in inside a brake system between the vehicle and the master brake cylinder.
During operation, a vacuum is present in the interior of the booster housing, with the result that the housing shells are pressed one against the other. In order to prevent the generally thin-walled booster housing from collapsing or imploding owing to the vacuum, two supporting formations are arranged on the connecting pin, which supporting formations support the booster housing from the inside—each supporting formation one of the housing shells.
For functional reasons, a restoring spring is arranged in the interior of the booster housing and acts with a prestressing force against the two housing shells. In order to prevent the brake booster from falling apart during its handling, transportation, despatching and the like up to the mounting of the master brake cylinder and/or mounting in the vehicle, the housing shells must be held together. In order, in this context, to avoid using separate, additional transportation securing devices, which have to be removed before the final mounting, it is known to connect the housing shells securely to one another at their radial outer edge. For this purpose, clips on one of the housing shells are often bent or positioned around a radial edge or band on another housing shell. This ensures that the prestressing force of the clamped restoring spring is received at the radial outer edge of the booster housing, and the housing shells are not pushed apart.
For the positioning of such clips, tools are required which ineffectively take up a large amount of space. In addition, in the case of surface-coated housing shells the surface coating or other protective coating is often damaged by the positioning of clips. This can lead during operation of the brake booster in the vehicle to undesired corrosion on the booster housing.